Idle speed control device



.Dec. 8, 1959 J. B. BURNELL ET AL 2,915,914

IDLE SPEED CONTROL DEVICE 2 Sheets-Sheet 1 Filed Feb. 10, 1958HTTOIPIVEY Dec. 8, 1959 J. B. BURNELL ETAL 2,915,914

IDLE SPEED CONTROL DEVICE 2 Sheets-Sheet 2 Filed Feb. 10, 1958 X; 1% Lm; m ma y W 4. 7 Z .v J m 1,

United States Patent IDLE SPEED CONTROL DEVICE Application February 10,1958, Serial No. 714,282

7 Claims. (Cl. 74-472) The present invention relates to an idle speedcontrol device for use with vehicles having high accessory loads andwhich loads are intermittently applied to the engine. The subject devicemay be applied to a vehicle having any type of accessory load whichrenders it necessary to control the carburetor in such a way as toeither maintain a constant engine idling speed whether the load is on or05 or which accessory load increase may require an increase in engineidling speed depending on certain conditions which will subsequently bediscussed.

The present idle speed control device is particularly adapted for usewith air conditioned vehicles in which the air conditioning mechanismvaries considerably the type of carburetor operation required.

Devices are known which are adapted to vary the engine idling speed inaccordance with changes in engine loading brought about byintermittently utilized accessories such as air conditioning. Suchdevices are shown in Patent Number 2,762,235 Berninger et a1. as well asin copending application Serial No. 436,872 Olson et a1., filed June 15,1954, now Patent No. 2,822,701. These and similar devices, however, havebeen found not to be sulficiently versatile to comprehend all'thevarious accessory load conditions under which the engine might beidling.

In general the prior devices will increase the engine idling speed overits normal value or maintain it: constant if the air conditioning unitis energized with'the engine being returned to its normal idling speedor normal throttle setting when the air conditioning system is shut off.In practice, however, there are found to be actually three distinctidling conditions which must be. accommodated with such a device if itis to function properly. Under the first condition, with the airconditioning unit oif the throttle setting must be such as toaccommodate normal engine idling which for illustrative purposes mightbe 450 r.p.m.

In the case of a' vehicle utilizing an automatictransmission, a secondsituation obtains when the transmission selector lever is in its driverange and the air conditioning unit on. Under these circumstances it isdesirable to maintain the engine idling speed at 450 r.p.m. In thiscase, it is necessary to provide means for increasing the throttleopening to overcome the increased en-, gine load represented by thefrictional resistance or drag in the transmission whereby the engineidling speedwill be maintained constant at the suggested 450 r.p.m. Ingeneral the prior art devices are capable of accommodating the first twoconditions of operation. However, there is a third condition which hasnot been achievable, in combination with the other two, by previousdevices. 7

This third condition obtains when the transmission selector lever is inthe park condition with the air conditioning unit on. Under theseconditions, that is, the vehicle idling at the curb, there is a highrate of under the h9od heat rejection. It is imperative that the engineidling speed be increased in order that the air con- 2,915,914 fPatented Dec. 8,1959

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. 2 ditioning mechanism may compensate for the high underhood heatrejection rate. If the prior art devices are adjusted so as to coverthistype of operation it will be apparent that under the second condition ofoperation, that is with the transmission selector lever in the driverange and the air conditioning unit on, that the engine idling speedwill be unnecessarily high increasing the tendency of the vehicle tocreep.

It is, therefore, the purpose of the present device to provide an idlespeed control device which is capable of three-position operationcorresponding to the three conditions of accessory-transmissionoperation set forth above. The subject device enables the engine idlingspeed to be more closely tailored to the load conditions to which theengine is subjected and which, therefore, insures engine idlingoperation which is more compatible with engine load requirements. 1

Other objectsand advantages of the present invention will be apparentfrom a perusal of the detailed description which. follows.

In the drawings:

1 Figure 1 is a' sectional elevational view of the throttle controlmechanism;

Figure 1a is a view' along line 1a-1a of Figure 1;

Figure 2 is'a schematic representation of the electrical control circuitfor the throttle control mechanism; and

Figures 3 through 5 represent the various operative positions of thethrottle control mechanism.

Referring to the drawings, the idle speed control device is indicatedgenerally at 10. Inasmuch as device 10 may be utilized with any typefuel system, no efi'ort will be made to illustrate the fuel systembeyond disclosing a throttle valve 12 rotatably mounted within aninduction passage 14. Thus it is apparent that the quantity ofcombustible mixture supplied to the'engine will be varied by rotatingthe throttle valve'12 to variably restrict the induction p'assage 14; av v The throttle valve 12 is suitably fixed to a shaft 16 to which anoperating arm 18 is also fixed. Throttle arm 18 terminates in a stopportion or projection 20 which, under conditions to besubsequentlydescribed, is adapted to coact with arr-adjustable stop'member'22 which forms a part of 'theflidl'e speed control mechanism,

At the outset it should be noted that the idle speedcontroldevice;10jisintended only-to control the idle speed and thusthe positionof'=throttle 12 under conditions when the airconditionin'g system '13 isoperative. Other wise the normal carburetor hotand cold idle stops arep;rovided for controlling the idling position of'thethrottle valve 12.Since the hot and cold idle stop members constitute no part of thepresent invention they have been eliminated from the drawings only tosimplifythe illustration of the present invention. Referring now tocontrol device 10, a bracket '24- is provided to permit the device to besuitably mounted on the engine with which it is to be associated. Theadjustable stop member 22 comprises the stud member 26 which isadjustably screwed into a sleeve 28, the other end of which is centrallyclamped to a diaphragm member 30. The diaphragm 30 is peripherallyclamped between casing members 32 and 34. Thus by rotatably adjustingstud member 26 with relation to sleeve 28 the maximum idle speed ofcontrol device 10 may be established.

A sleeve or supporting tube 36 is centrally mounted to casing 32 and isadapted to slidably support the sleeve member 28 therewithin. Forreasons which will be apparent subsequently, sleeve 28 is provided witha seal 38 which slidably cooperates with supporting tube 36 to maintainthe chamber 40 defined by casing 32 and diaphragm 30 substantiallyairtight. The supporting tube 36 is fixed to casing 32 by bending orspinning over the r merit 50 abuts while the other end inner endsthereof so as to fixedly mount the tube to the casing. As shown inFigure. 1 the control device supporting bracket 24 is fixed to tube 36and therethrough supports the remainder of control device 10.

A radial flange ."42-is;f orrn,ed at the other. end of. tube 1 36 andprovides an; outer stop: fora dished shapespring insert 54.- "Thus oncethe. a'xialfpositioncof the-disc 52 is established it will notvary'therefrom unless. anadjust ment is made for reasons which willsubsequently be' con sidered. Disc 52 and spring.:seati.44are"so relatedthat upon the axial movement pfislee've 28.10 the right, or idle speeddecreasingQdirection, the .disciwill. engage'tlie seat;

Continued rightward movement .of the. sleeve and disc will cause spring50 to be compressed :untilsuchtim'e. as

the inner end 56 of seat-44 abuts'againstthe spring .seat 46 which endsthe movement of adjustablestopi22; I

Reinforcing washers 58-.are provided on either side of position inwhich"; it abuts tube the diaphragm in order;to protect the diaphragmand 7 also to provide a rigid surface adaptedto 'coact with an annularridge 60 formedon casing member .34. Ridge 60 provides a stop limitingthe leftward or throttle opening position of adjustable stop 22.

The means for controlling the actuationof diaphragm 30 will nowhedescribed- The diaphragm supporting casing 34 is elongated, orotherwise formed, to provide a cylindrical portion 62 adapted to housecontrol devices which willsubsequently be described. Casing portion 62is divideclby a wall section 64 which cooperateswith diaphragm 30 toprovideacontrol chamber 66. Wall 64 and the remainder of casing 62 incombination with. a cover p late 68 define an additional chamber70vented to atmosphere through vent port 7 Casing 62 and moreiparticularlywall 6 4 are formed to provide an .enlarge'dbossiportion 72 whichthreadably receives. a. pipefifsection 74 adaptedto communicate througha T-plug 76 with a source of vacuum. 'A, passage 78 is drilledthroughwall 64-,and communicates pipe 74 andis closed at its other end by. plug80*; Passage78 includes a restrictionor orifice 82 therein which reducesthe vacuumforce adapted to act on diaphragm 30.

Passage 78; communicates through an opening or passage 84 withdiaphragmchamber 66. p r

Casing wall 64 alsoincludesia transverse passage 86 ntersecting passage78 andopen at its inner end to communicate with chamber 70. A spindletype valve member 88 is slidably mounted'in transverse. passage 86andincludes acyIindrical land portion 90 and a frustro-conical land portion92. The .frustro-conical land portion 92 is disposedmainly exteriorly oftransverse passage 86 and s adapted to control the degree ofcommunication between the transverse passage and chamber 70. Cylindricalland 90, on theother hand, controls the vacuum which may be introducedinto chamber 66., r

solenoid 94 is mounted on end plate 68 so as to be disposed withinchamber 70 in axial alignment with the sp ndle valve 88. A disc-likearmature member 96 is fixedly mounted to the spindle valve 88 proximatethe frustro-conical land 92. A spring member 98 is seated w thin theCore of the solenoid 94and-is adaptedto bias armature and the spindlevalve 88 to the left when the solenoid isnot energized; In this way; thefrustro-conical land 92 will blockthetransverse passage 86 from communicating with the chamber 70., At the-same time, cy.-. lindricall'and 90will permit the vacuum. introducedf fqm atone end with the boss 72. andr pipe 74 to communicate with the diaphragm chamber 66. By means to besubsequently discussed, solenoid 94 is adapted to be energized when thevehicle gearshift lever 100 is in its park position.

An additional solenoid device 102 is provided for superimposing acontrol force on the device 10 which reflects the operative condition ofthe air conditioning unit. Solenoid device 102 will now be described.The T-plug 76 mounted on pipe 74 provides a boss 104 which threadablysupports solenoid casing 106. A solenoid coil is disposed within casing106 which is enclosed by end plates 108 and 110. End plate 108 includesa passage 112 which communicates through a restricted portion 114 withthe T-plug and hence the source of vacuum.

A tube 116 is adapted to seat within an enlarged portion of end plate108 and is supported at its other end upon a boss 118 extending inwardlyfrom end plate 110. Casing boss 118 includes a longitudinally extendingpassage 120 therethrough which communicates the interior. of tube 116with the atmosphere.

An'axially fluted armature-valve member 122 is slidably supported.within tube 116 and includes a tapered end portion.124 adapted to coactwith the longitudinally extending boss passage 120 to block the fiowtherethrough when solenoid l2l isenergized. However, a spring member 126 disposedb'etween boss 118 andthe slidable valve member 122' urges thevalve member to the. left which communicates the end casing passage 112'with the atmosphere. r

A conduit 128 communicates with end casing passage 112 and at its otherend with an opening 130 in diaphragm casing 32. Thus with the solenoidcontrolled fluted valve 122 in the position shown in Figure *1 thediaphragm control chamber. 40 is vented to the atmosphere.

The means for controlling the solenoids 94 and 121 is shownschematically inFigure Z andwill now be described. Transmissionselector. lever 100 is rotatable about its pivot point132 to the varyingpositions indicated by the letters P, N, D, Loand R signifying thevarious operating conditions of the transmission. A transmissionselector lever controlled switch is indicated generally at 134 andincludes a movable contact member 136 articulated through a lever 138and a link 140 tothe transmis sion selector lever. The movable contactlever 138 is pivoted at 142 and is connected through a lead 143 with thevehicle battery 1 44. Switch 1134 includes the fixed terminals indicatedat N and P which correspond to the transmission selector lever positionsrepresented by neutral and park. The fixed terminals N and-P'connectthrough a lead v146 with solenoid 94.

A switch 148 controlled by the air conditioning actuat- 7 ing mechanismis interposedinlead143 between the battery 144 and the movablecontact136 ofswitch 134. The movable contact .136, througha lead 150,energizes solenoid 121 whenever the air conditioning switch 148- isclosed. With theair conditioning switch closed and the transmissionselector lever'in either the neutral or park positions, both solenoids94 and 121 will be'energized.

Referring especially to Figures 3, 4 and 5 in conjunction with Figure 2,the operation 'of the control device 10 is as follows. With the airconditioning switch 148 off or open both solenoids 91 and 121 will bedeenergized as shown in Figure 2. Under this condition diaphragm chamber40 will be vented to the atmosphere through conduits 120, 112 and 128.With the solenoid 121 deenergized, restricted passage 114 will provide alimited atmospheric bleed in vacuum pipe 74. However, the vacuum forcein the pipe and hence the remainder of the system is not seriouslyatfected by such bleed; Further, inasmuch as solenoid 94 is alsodeenergized, spindle valve land 92 will block the communication oftransverse passage 86 with atmospherically vented chamber 70 and at thesame time .will permitthe vacuum forcein passage 781.to.be communicatedto diaphragm chamber 66-Which will cause the. diaphragmlto. be moved tothe right as seen in Figures 1 and 3. Under these conditions sleeve disc52 will engage flange 48 of spring seat 44 compressing spring 50 andmoving the adjustable stop 22 to its rightmost position. As a result,throttle valve 12 is positioned by its normal stop members to provide anappropriate idling speed which for illustrative purposes may be 450r.p.m.

Next with the air conditioning switch 148 on and the transmissionselector lever 100 moved to any ofthe drive positions (D, L0 or R) itwill be appreciated that it will be necessary to increase the degree ofopening of throttle 12 to maintain a constant, e.g. 450 r.p.m., engineidling speed in view of the air conditioning load now imposed on theengine. Accordingly, the movable contact 136 is out of engagement withthe fixed contacts N or P under which condition only the solenoid 121 isenergized. Under this condition the solenoid controlled fluted valve 122blocks the atmospheric bleedpassage 120 which permits manifold vacuum tobe communicated through passages 114, 112 and 128 to diaphragm chamber40. In this way the vacuum forces in chambers 40 and 66 substantiallyneutralize each other. Spring 50, therefore, will now expand and in sodoing move the spring seat 44 and with it disc 52 to the left untilflanged end 56 of spring seat 44 engages the annular flange 42* of tube36 leaving the elements in the position shown in Figure 4. In thisposition the adjustable stop 22 en-' gages the projection 20 of thethrottle arm 18 and opens the throttle sufliciently to maintain thedesired engine idling speed, e.g. 450 r.p.m.

In the event the vehicle is now parked at the curb with the enginerunning and the air conditioning unit on it has been found that the rateof heat rejection under the hood is considerably increased. To provideforproper functioning of'the air conditioning system, it is necessary toincrease the engine idling speed by an appreciable amount which againfor illustrative purposes may be considered to be as much as to 900r.p.m. Thus with the transmission selector lever now in either theneutral or park position, solenoid 94 will also be energized. Under thiscondition, the spindle valve 88 is moved to its rightmost position bythe armature disc 96 causing the cylindrical land 90 to block the flowof vacuum to diaphragm chamber 66 and at the same time permittingthefrustroconical land 92 to open said chamber to the atmosphericallyvented chamber 70. Now manifold vacuum is acting only in diaphragmchamber 40. which causes the diaphragm to be moved still further to theleft, as shown in Figure 5, until the left diaphragm reinforcing disc 58abuts the annular shoulder 152 formed on diaphragm casing member 32.This further leftward movement of the-diaphragm 30 will cause the sleeve28 and the disc 52 to move relative to the spring seat 44 and to movethe throttle valve 12 to a more fully opened position which will causethe engine idling speed to be increased in the amount already suggested.

While the mechanism shown in the drawings is fully operative to providethe three throttle settings, as described, it is apparent that variousstructural modifications may be made in the subject device within thescope of the invention comprehended by the hereinafter appended claims.

We claim:

1. Apparatus for controlling the idling speed of the engine of anautomotive vehicle comprising in combination an induction passage forsupplying a combustible mixture to said engine, a throttle valve in saidpassage for controlling the quantity of flow therethrough, means forapplying an accessory load to said engine, a transmission selector levermovable to a plurality of driving and non-driving positions, means formoving the throttle toward open position for increasing the idling speedof the engine, a first device controlled by said accessory loadcontrolling means, a second device controlled by said transmissionselector lever, said first and second devices cooperating to maintainthe throttle moving means in an inoperative position relative to thethrottle valve when the accessory load is not applied and thetransmission selector lever is in one of its driving positions wherebythe throttle valve is disposed in its normal idle position, saidfirstdevice being adapted to permit said throttle moving means'to open saidthrottle valve to a second position when said accessory load is applied,and said second device being adapted to permit said throttle movingmeans to position said throttle valve in a third position more opcn thanthe second when said transmission selector lever is placed in one of itsnon-driving positions with the accessory load applied.

2. Apparatus for controlling the idling speed of the engine of anautomotive vehicle'comprising in combination an induction passage. forsupplying a combustible mixture to said engine, a. throttle valve insaid passage for controlling the quantity of flow therethrough, switchmeans for applying an accessory load to said engine, a transmissionselector lever movable to a plurality of driving and non-drivingpositions, switch means adapted to be actuated by the selector leverwhen in a non-driving position, means for moving the throttle towardopen position for increasing the idling speed of the engine, a firstsolenoid device controlled by said accessory switch means, a secondsolenoid device controlled by said transmission selector lever switchmeans, circuit means electrically'interconnecting the firstand secondsolenoid devices and the throttle moving means whereby said devicescooperate when deenergized to maintain the throttle moving means in aninoperative position relative to the throttle valve when the accessoryload is not applied and the transmission selector selectorlever is inone of its driving positions whereby the throttle valve is disposed inits normal idle position, said first solenoid device when energized bythe accessory switch means being adapted to permit said throttle movingmeans to open said throttle valve to a second position, and said secondsolenoid device when energized by the selector lever switch meansbeing-adapted-to permit said throttle moving means to position saidthrottle valve in a third position more open than the first.

3. An apparatus for controlling the idling speed of the engine of anautomotive vehicle comprising in combination an induction passage foradmitting a combustible charge to said engine, a throttle valve disposedin said passage for controlling the quantity of flow therethrough, aservo mechanism for moving the throttle toward open position forincreasing the idling speed of the engine,

said servo mechanism comprising a casing having a movable memberdisposed therewithin, said casing and movable' 'member defining a pairof chambers on opposite sides' of said movable member, conduit meansadapted to admit a vacuum control force to both of said chambers, afirst valve means normally biased to a position venting one of saidchambers to atmosphere, a second valve means normally biased to aposition admitting said vacuum force to the other of said chamberswhereby said servo mechanism is rendered inoperative to position thethrottle valve whereby the throttle valve is disposed in its normal idleposition, means for shifting said first valve means to a positionblocking said atmospheric vent in which condition the vacuum force isadmitted to both of said chambers permitting the servo mechanism to movesaid throttle valve to a second idle position, and means for moving saidsecond valve means to a position in which the associated chamber isvented to atmosphere permitting said servo mechanism to move saidthrottle valve to a third idle position.

4. An apparatus for controlling the idling speed of the engine of anautomotive vehicle comprising in combination an induction passage foradmitting a combustible charge to said engine, a throttle valve disposedin said passage for controlling the quantity of flow therethrough, aservo mechanism for moving the throttle toward open position forincreasing the idling speed of the engine,

bers, a first valve means normallybiased to a position venting one ofsaid chambers, to atmosphere, asecond valve means normally biased to aposition admitting said vacuum-force to the other of said chamberswherebysaid servo mechanism is rendered inoperative to position; thethrottle valve whereby the throttle valve is disposed in its normal idleposition, a solenoid for shiftingsaid first valve means to a positionblocking said atmospheric vent in which condition the vacuum .forceisadmitted to both of said chambers permitting the servo mechanism to movesaid throttle valve to, a second idle position, and a solenoid formoving said second valve means to a position in which the associatedmember is vented to atmosphere permitting said servo mechanismto movesaid throttle valve to a third idle position. p 5. An apparatus forcontrolling the idling speed of an engine as set forth in claim 3 inwhich said servo mech-' anism includes a control rod fixed to saidmovable memher and which rod is adapted to actuate said throttle valve,a flange member fixed for movement with said control rod, a sleevemember slidably mounted with respect to said control rod for axialmovement relative thereto, spring means biasing said sleeve intoengagingposition 'with said flange member to move the control rod in athrottle opening direction, stop means to limit the throttle openingmovement of said sleeve, said flange member being adapted to engage saidsleeve and compress said spring means when said servo mechanism is inits inoperative position, said spring means being adapted to move said.sleeve, flangemember and said control rod 7 to position the throttlevalve in said second idleposition when said vacuum force is admitted toboth of said servo chambers, and said flange member and controlrod beingmoved axially away from said sleeve to position said throttle valve insaid third idle position when said vacuum force is admitted to the firstvented servo chamber.

6. An apparatus for controlling the idling speed of an engine of anautomotive vehicle comprising in combination an induction passage foradmitting a combustible charge to said engine, a throttle valve disposedin said passage for controlling the quantity of flow therethrough, aservo mechanism for moving the throttle toward open position forincreasing the idling speed of the engine, said servo mechanismcomprising a diaphragm having chambers formed on opposite sides thereofin open communication with said diaphragm, first conduit meanscommunicating with one of said chambers, second conduit meanscommunicatingwith the otherrof said chambers, a common source of vacuumcommunicating with each of said conduit means, first and second valvemeans respectively disposed insaidufirst and second conduit, means,

each of said valve means being adapted to communicate its associatedservo chamber with said vacuum source or with the atmosphere wherebysaid servo mechanism may move the throttle valve to a plurality of openpositions.

engine of an automotive vehicle comprising in combination an inductionpassage for admitting a combustible charge .to said engine, a throttlevalve disposed in said passage for controlling the quantity of'flowtherethrough, a servo mechanism for moving the throttle toward openposition for increasing the idling speedof the engine, said servomechanism comprising a. diaphragm having chambers formed on oppositesides thereof inopen communication with said diaphragm, first conduitmeans communicating with one of said chambers, second conduit meanscommunicating with the other of said chambers, a common source of vacuumcommunicating with each of said conduit means, first and second valvemeans respectively disposed in said first and second'conduit means, aspring member normally biasing the first valve means to vent the firstconduit means and associated diaphragm chamber to the atmosphere, aspring member ,normally biasing the second valve means to admit vacuumto the second conduit means to shift the diaphragm to a positionpermitting the throttle valve to assume a first idle position, meansshifting the firstvalve to admit vacuumto the second conduit meanspermitting the throttle valve to assume a second idle position and meansfor opening the second valve means to atmosphere whereby the diaphragmshifts the throttle valve to a third idle position.

References Cited in the file of this patent UNITED STATES PATENTS 7. Anapparatus for controlling the idling speed of an

